He carried food with him underground, which suggests either that he planned to be in the cave for an extended period or that eating before difficult work was standard practice.

He wore a shell necklace, a personal ornament that connects him to the material culture of his community.

He was wearing a blanket or robe, practical warmth for a 54-degree cave environment.

He had been to this ledge before, or to others like it.

He knew the route, or was with people who knew it.

He carried the tools his work required — the mussel shells, presumably, and whatever containers he was using to collect the gypsum.

He was working when the boulder moved.